An electromagnetic wave absorbing material and a method for preparing the same are disclosed. The electromagnetic wave absorbing material consists of liquid resin, carbon nanocapsules, carbon fiber and hollow glass microsphere. All components are mixed well to form the electromagnetic-wave absorbing material. The method for preparing the electromagnetic-wave absorbing materials includes steps of: mixing the liquid resin, carbon nanocapsules, carbon fiber and hollow glass microsphere well to form a slurry solution; pour the slurry solution into a mold; after curing and cooling, an electromagnetic-wave absorbing material is obtained. The electromagnetic-wave absorbing material with density ranging from 0.75 to 1.0 g/ml matches requirements of compact design and light weight in high technology industries.